1. STRUCTURES OF THE CELL MEMBRANE

2. Review Importance
All organisms need to maintain a balance in their internal environment.
This balance is called?
Homeostasis
The components of the cell membrane control the movement of molecules into and out of the cell. This is called?
Selective permeability

3. The phospholipid layer ( the cell membranes basic framework)
A phospholipid consists of a polar portion, called the head,
and two longer fatty acids, called the tail.
Thus a phospholipid molecule is represented as a sphere with two long projections.

4. When mixed with water, the heads are attracted to polar water molecules (hydrophilic).
The nonpolar tails move as far from water as possible (hydrophobic), and a double layer of phospholipids with tails to the interior results.

5. Function of the phospholipid layer
Creates a soft, flexible, stable and fluid covering for the cell
Fatty layer allows O2 and CO2 which are fat soluble to pass through.
What would be the purpose of this?
Impermeable to water soluble substances such as amino acids, sugar, protein, nucleic acids and various ions.

6. Organic molecules in the cell membrane
There are two types of proteins in the cell membrane
1. Integral (transmembrane) proteins pass
through the entire membrane
2. Peripheral proteins do not protrude into the
phospholipid layer
Some of the phospholipids and integral proteins have carbohydrate chains attached to them forming glycolipids and glycoproteins.
Cholesterol is also found within the membrane of animal cells to provide support and structure

7. 2 3 1 4 6 5
Word Bank: Carbohydrate Chains, Cell Membrane, Cholesterol, Integral Protein, Peripheral Proteins, Phospholipids

8. Function of protein structures

9. Cell Membrane Quiz